Reuters – U.S. President Barack Obama addresses the Iranian people, in this frame grab of videotaped speech released …

WASHINGTON (Reuters) – President Barack Obama issued an unprecedented videotaped appeal to Iran on Friday offering a "new beginning" of diplomatic engagement to turn the page on decades of U.S. policy toward America's longtime foe.

"My administration is now committed to diplomacy that addresses the full range of issues before us, and to pursuing constructive ties," Obama said in a message released to select Middle East broadcast outlets timed for an Iranian holiday celebration.

Obama went further than he has since taking office on January 20 in extending an olive branch to Tehran, which has been locked in bitter disputes with Washington over Iranian nuclear ambitions and support for militant Islamic groups.

The Obama administration -- in a major shift from former President George W. Bush's isolation policy toward Iran, which he once branded part of an "axis of evil" -- has expressed an openness to face-to-face diplomatic contacts with Tehran.